Computed Tomography as a Method for Age Determination of Carnivora and Odontocetes with Validation from Individuals with Known Age

• Published in: Animals
• Main Authors: Baier-Stegmaier, Sina, Gundlach, Carsten, Chriél, Mariann, Hansen, Mette Sif, Vedel-Smith, Christina, Hansen, Charlotte Vikkelsø, Johansson, Daniel Klingberg, Henriksen, Louise Birgitte, Wahlberg, Magnus, Thøstesen, Charlotte Bie, Alstrup, Aage Kristian Olsen, Gregersen, Kristian Murphy, Pertoldi, Cino, Pagh, Sussie
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2023
• Subjects: American mink; Carnivore age; Computed tomography; Harbor porpoise; Micro-CT; Museum collections; Neogale vison; Phocoena phocoena; Red fox; Toothed whale age; Vulpes vulpes; X-ray; µ-CT; toothed whale
• Online Access: https://orbit.dtu.dk/en/publications/aadb5759-def6-4829-99ee-5f6c23c2c395; https://doi.org/10.3390/ani13111783; https://backend.orbit.dtu.dk/ws/files/328099656/animals_13_01783_v4.pdf

Traditional methods for age determination of wildlife include either slicing thin sections off or grinding a tooth, both of which are laborious and invasive. Especially when it comes to ancient and valuable museum samples of rare or extinct species, non-invasive methods are preferable. In this study, X-ray micro-computed tomography (µ-CT) was verified as an alternative non-invasive method for age determination of three species within the order of Carnivora and suborders Odontoceti. Teeth from 13 red foxes (Vulpes vulpes), 2 American mink (Neogale vison), and 2 harbor porpoises (Phocoena phocoena) of known age were studied using µ-CT. The number of visible dental growth layers in the µ-CT were highly correlated with true age for all three species (R 2 = 96%, p < 0.001). In addition, the Bland–Altman plot showed high agreement between the age of individuals and visible dental layers represented in 2D slices of the 3D µ-CT images. The true age of individuals was on average 0.3 (±0.6 SD) years higher than the age interpreted by the µ-CT image, and there was a 95% agreement between the true age and the age interpreted from visible dental layers in the µ-CT.